VIII MAY-FLIES 295 



before, I will not however lament, with Clutius, the 

 rarity of books dealing with this subject. Nature is 

 the best revealer of her own wonders. Though books 

 may be useful, if they truly represent the phenomena 

 of nature, I pity those who trust to the observations 

 of others, and impose fictions upon themselves and 

 their readers. 



" I will describe the methods which in the year 

 1670 I employed to investigate the anatomy of the 

 larva. 



" The male, which is easily distinguished by its 

 large eyes, is fastened with the finest needles, back 

 downwards, upon black paper or linen in a wooden 

 dish. Then having cut through the skin, we see a 

 watery fluid flow out, which is the true blood of the 

 animal, though it is not red in colour as in the Earth- 

 worm or in Quadrupeds. I have found nothing better 

 for opening the skin than fine scissors, for lancets, 

 however sharp, tear the parts. Then with the finest 

 scalpel, or the point of a needle, the skin is gently 

 separated from the parts beneath. Under the skin 

 is found a delicate membrane, and beneath this the 

 muscles of the body-wall, some of which pass directly 

 from one segment to another, others obliquely or 

 transversely. Others again serve for moving the 

 limbs. Within the muscles is a very delicate mem- 

 brane, upon and within which lies the fat, consisting 

 of minute white vesicles. Next we find the oesophagus, 

 stomach and intestine. The oesophagus, like a thin 

 thread, passes from the mouth into the thorax, and 

 expands to form the crop. The crop, when distended 

 with food, or with air injected from a fine glass tube, 



